Field
The present disclosure relates to an organic light emitting device, and more particularly, to an organic light emitting device including an organic light emitting element which has a simple structure and thus can be easily manufactured, and also has improved color gamut, luminous efficiency, and lifetime.
Description of the Related Art
Recently, as the world entered the information age, the field of display for visually displaying electrical information signals has grown rapidly. Thus, various display devices that are thinner, more lightweight, and require low power consumption have been developed.
Specific examples of the display devices include a Liquid Crystal Display (LCD) device, a Plasma Display Panel (PDP) device, a Field Emission Display (FED) device, an Organic Light Emitting Device (OLED), and the like.
Particularly, the OLED is a display device using an organic light emitting element as a self-light emitting device. Further, the OLED has the advantages of high response speed, a high luminous efficiency, a high brightness, and a wide viewing angle as compared with the other display devices.
The organic light emitting element has a basic structure in which an organic emitting layer is disposed between two electrodes. Electrons and holes are injected into the organic emitting layer from the two electrodes, respectively, and the electrons and holes are combined into excitons in the organic emitting layer. When the generated excitons transition from an excited state to a ground state, light is emitted from the organic light emitting element.
An organic light emitting element may be a component in each the of sub-pixels respectively emitting red (R), green (G), and blue (B) lights. The sub-pixels each including the organic light emitting element constitute a pixel that realizes a full color gamut. Lights emitted from the red (R), green (G), and blue (B) sub-pixels have their own color coordinates respectively corresponding to red (R), green (G), and blue (B). A color gamut of the corresponding pixel can be expressed on the basis of the color coordinates respectively corresponding to red (R), green (G), and blue (B). Color coordinates are characteristic values of the light emitted from an organic light emitting element and thus determined depending on the material of an organic emitting layer. A color gamut of an organic light emitting element is an important factor in determining the excellence in image quality of an organic light emitting device (OLED). Further, a luminous efficiency of an organic light emitting element is an important factor in determining the excellence in lifetime of an OLED. Furthermore, a driving voltage of an organic light emitting element is an important factor in determining the excellence in power consumption of an OLED. In reaction to demands of the market for display devices having high image quality, long lifetime, and low power consumption, research and development for an organic light emitting element having a high color gamut and a high luminous efficiency with a low driving voltage continues to take place.
However, the organic light emitting element having a high color gamut and a high luminous efficiency may require a complicated structure. The complicated structure of the organic light emitting element means that its manufacturing process becomes complicated. As the complexity of the manufacturing process is increased, the yield of the OLED is decreased, which precludes any reduction in the production cost of the OLED. Further, a high-priced dopant material doped on an organic emitting layer also precludes any reduction in the production cost of the OLED.